--- title: "uqlm vs ell" type: "comparison" canonical_url: "https://www.graphcanon.com/compare/cvs-health-uqlm-vs-madcowd-ell" tools: ["cvs-health-uqlm", "madcowd-ell"] --- # uqlm vs ell *GraphCanon updated Aug 8, 2026* ## Verdict Pick uqlm if uqlm offers specialized Python capabilities for quantifying uncertainty to improve confidence in language model outputs and reduce hallucinations; pick ell if ell is a Python-based language model development library and prompt engineering tool. [uqlm](https://cvs-health.github.io/uqlm/latest/index.html) reports 1.2k GitHub stars, 129 forks, and 25 open issues, last pushed Aug 3, 2026. [ell](http://docs.ell.so/) has 5.9k stars, 343 forks, and 186 open issues, last pushed Jun 5, 2025. Figures are from public GitHub metadata via [uqlm's repository](https://github.com/cvs-health/uqlm) and [ell's repository](https://github.com/MadcowD/ell). | | [uqlm](/tools/cvs-health-uqlm.md) | [ell](/tools/madcowd-ell.md) | | --- | --- | --- | | Tagline | A Python package for uncertainty quantification in LLM hallucination detection | A language model programming library | | Stars | 1,188 | 5,869 | | Forks | 129 | 343 | | Open issues | 25 | 186 | | Language | Python | Python | | Adopt for | uqlm offers specialized Python capabilities for quantifying uncertainty to improve confidence in language model outputs and reduce hallucinations. | ell is a Python-based language model development library and prompt engineering tool. | | Persona | - | - | | Runtime | - | - | | License | Apache-2.0 | MIT - Permissive free software license | | Categories | Evaluation & Observability | LLM Frameworks | ## Trust and health _Sourced signals - not a safety guarantee. No winner column._ | | [uqlm](/tools/cvs-health-uqlm.md) | [ell](/tools/madcowd-ell.md) | | --- | --- | --- | | Maintenance | Very active (96%) | Dormant (18%) | | Days since push | 4d | 417d | | Open issues (now) | 25 | 186 | | Owner type | Organization | User | | Full report | [trust report](/tools/cvs-health-uqlm/trust.md) | [trust report](/tools/madcowd-ell/trust.md) | ## Shared compatibility - **Python**: [uqlm](/tools/cvs-health-uqlm.md) - Python runtime; [ell](/tools/madcowd-ell.md) - Python runtime ## Decision facts: uqlm - **Adopt for:** uqlm offers specialized Python capabilities for quantifying uncertainty to improve confidence in language model outputs and reduce hallucinations. ## Decision facts: ell - **Pricing:** freemium - Free to use under MIT License, with no premium plans mentioned. - **Adopt for:** ell is a Python-based language model development library and prompt engineering tool. - **License detail:** MIT - Permissive free software license ## Choose when ### Choose uqlm if… - License: uqlm is Apache-2.0, ell is MIT. - Tags unique to uqlm: ai safety, ai-evaluation, confidence-estimation, hallucination-detection. - Also covers Evaluation & Observability. - When precise estimation of confidence scores is needed to ensure reliability in language model predictions. ### Choose ell if… - License: ell is MIT, uqlm is Apache-2.0. - Pricing: Free to use under MIT License, with no premium plans mentioned.. - Tags unique to ell: ai, prompt-engineering. - Also covers LLM Frameworks. - When you require a dedicated Python framework for developing custom language models and fine-tuning them with specific prompts for your application. ## When NOT to use uqlm - If working exclusively with non-language-based machine learning models, as uqlm focuses on text outputs from LLMs. - When simple plug-and-play performance metrics suffice; uqlm requires a more intricate setup for uncertainty quantification and confidence estimation. ## When NOT to use ell - If you prefer JavaScript or other languages over Python, consider alternative frameworks that support the language of your choice. ## Common questions ### What is the difference between uqlm and ell? uqlm: A Python package for uncertainty quantification in LLM hallucination detection. ell: A language model programming library. See the comparison table for live GitHub stats and shared categories. ### When should I choose uqlm over ell? Choose uqlm over ell when License: uqlm is Apache-2.0, ell is MIT; Tags unique to uqlm: ai safety, ai-evaluation, confidence-estimation, hallucination-detection; Also covers Evaluation & Observability; When precise estimation of confidence scores is needed to ensure reliability in language model predictions. ### When should I choose ell over uqlm? Choose ell over uqlm when License: ell is MIT, uqlm is Apache-2.0; Pricing: Free to use under MIT License, with no premium plans mentioned.; Tags unique to ell: ai, prompt-engineering; Also covers LLM Frameworks; When you require a dedicated Python framework for developing custom language models and fine-tuning them with specific prompts for your application. ### When should I avoid uqlm? If working exclusively with non-language-based machine learning models, as uqlm focuses on text outputs from LLMs. When simple plug-and-play performance metrics suffice; uqlm requires a more intricate setup for uncertainty quantification and confidence estimation. ### When should I avoid ell? If you prefer JavaScript or other languages over Python, consider alternative frameworks that support the language of your choice. ### Is uqlm or ell more popular on GitHub? ell has more GitHub stars (5,869 vs 1,188). Stars measure visibility, not whether either tool fits your constraints. ### Are uqlm and ell open source? Yes - both are open-source projects on GitHub (uqlm: Apache-2.0, ell: MIT). ### Where can I find alternatives to uqlm or ell? GraphCanon lists graph-backed alternatives at [uqlm alternatives](/tools/cvs-health-uqlm/alternatives) and [ell alternatives](/tools/madcowd-ell/alternatives) ([uqlm markdown twin](/tools/cvs-health-uqlm/alternatives.md), [ell markdown twin](/tools/madcowd-ell/alternatives.md)), ranked by typed relationship edges rather than popularity votes. ### Is there a machine-readable version of this comparison? Yes. The markdown twin at [this comparison](/compare/cvs-health-uqlm-vs-madcowd-ell.md) mirrors this page for agents and LLM crawlers, with the same stats table and FAQ answers. ### Which is better maintained, uqlm or ell? uqlm: Very active. ell: Dormant. Compare maintenance labels, days since push, and release cadence in the trust section below - stars alone do not measure maintenance. ### Where are the full trust reports for uqlm and ell? GraphCanon publishes per-repo trust reports with dated maintenance, provenance, and scan summaries: [uqlm trust report](/tools/cvs-health-uqlm/trust); [ell trust report](/tools/madcowd-ell/trust). --- **Machine-readable endpoints** - JSON: [`/api/graphcanon/graph?tool=cvs-health-uqlm`](/api/graphcanon/graph?tool=cvs-health-uqlm) - LLM index: [/llms.txt](/llms.txt) - Full corpus: [/llms-full.txt](/llms-full.txt) _GraphCanon - The knowledge graph for AI development. https://www.graphcanon.com/_